This invention relates in general to the construction of air filters and, more specifically, filters for industrial applications, i.e. compressors, vacuum pumps and the like; and in particular, a new and useful filter wherein it is now possible to replace the filter element inexpensively without having to discard and replace the more expensive container as has been done in the past. The filter element chosen in this primary example is a filter formed of a folded fiber filter material with the filter element being captured and retained by a plurality of inter-engaging ribs and fingers which project into the recesses created by the folding of the fibrous filter element. Disengagement of the ribs and fingers permits the removal of the soiled filter and introduction of a new clean filter element.